Furnace



G. P. WARD Aug. 27, 1929.

FURNACE Filed Nov. 28, 1923' -INVENTOR.

Patented Aug. 27, 1929.

UNITED STATES- PATENT OFFICE.

GEORGE PALMER WARD, OF HABANA, CUBA. ASSIGNOR, BY MESNE ASSIGNMENTS, TO FULLER LEHIGI-I COMPANY, A CORPORATION OF DELAWARE.

FURNACE.

Application "filed November 28, 1923. Serial No. 677,532.

My present invention relates to a furnace associated with a steamboiler and provided with separate fire boxes in which solid fuel and fluid fuel may be burned, respectively.

One of the objects of my invention is to provide a compact arrangement in' which either fuel may be used separately or both in combination with eflicient results. Another object of my invention is to provide an arrangement inwhich the two fire boxes may be combined in a compact manner and so that the operation of either one will not be interfered with by the presence of the other. With these and other objects in view, my invention consists in the arrangements and constructions hereinafter described and more specifically pointed out in the appended claims.

- In the drawings I have illustrated one embodiment of my invention 1n a furnace con.- nected to a Stirling boiler of a known type, with the fire boxes arranged to burn bagasse and oil, respectively.

The boiler has three upper steam and water drums 10, 11 and 12 and a mud drum 13 con- .nected by vertically inclined banks of water tubes 14, 15 and 16, the boiler being placed in a setting over a combustion chamber 17.

A wall-18 replaces the usual front furnace wall for such a boiler and through it is a gas inlet '19 connecting with a combustion chamber or gas passage 20 separated from the bagasse fire box proper 21 by a bridge Wall 221. The bagasse may be supplied through an opening 22 in the roof of the fire box and access openings 23 and 24 are provided through which the fire may be reached by the operator of the furnace.

Above the gas passage 20 and located so as not to interfere with the bagasse feed. opening 22 is a fluid fuel fire box or combustion chamber 25 provided with an oil burner 26 at its front end and having a connection through the opening 27 with the combustion chamber 17.

Preferably, the front bank of tubes 14 which constitutes the rear of the combustion chamber 17 is provided with a baifle 28 extending upwardly from the mud drum 13 and terminating short of the drum 12. This bafiie 28 may be located in front of the entire bank, but preferably I locate it behind one or more rows of tubes of this front bank. At the rear of the bank 14 is a bafile 29extending downward along the tubes of thebank 15 from rear of the bank 15. A gas outlet 31 is provided at the lower rear part of the setting.

In operation, bagasse is charged into the fire box 21 and burned, the heated gases there-- from passing through the gas passage 20 where they are more thoroughly combined and burned, and from thence pass through the opening 19 into the lower part of the combustion chamber 17. For some purposes, and at some stages of the operation, the heat derived from this burned bagasse will be sufficient. In the event that the supply of bagasse is insufficient for steaming purposes or does not give the amount of heat desired, then the burner 26 may be brought into action, access to the burner being had without interfering with the bagasse supply through the opening 22. The hot gases from the oil burned in the fire box 25 will pass through the opening 27 into the upper part of the combustion chamber 17. It will be understood that, if desired, the bagasse furnace alone or the oil burner alone may be in operation.

By the arrangement which I have-shown it will be clear that both of these fire boxes may be located in front of the boiler, so that the gases from each of them may enter the combustion chamberthereof and pass to the boiler tubes in an efficient manner. The boiler tubes are preferably screened from the direct radiant heat of the solid fuel furnace by the Wall 18 and the bridge wall 221 whilethe boiler there would be no baflle located in front of the tubes of the bank 14. With this latter construction, the'gases from the oil burner may pass over the top of such a bafile without contacting with the tubes in the first bank, so that the heat therefrom would be absorbed only by the, tubes in the middle and last bank. By

providing the baflle arrangement which I have illustrated, it will be seen that the gases from both the bagasse and the oil follow substantially the same path and contact with all of the tubes of the boiler. This last would be completely true if the bafiie 28 were placed in front of all of the tubes in the bank 14:. I prefer to place it behind one or more rows, however, so that the baffle will be protected from the direct heat of the gases from the bagasse fire box.

'It will be understood that the arrangement which I have shown is merely illustrative, and that my invention may be widely varied in its application. While I have shown a boiler of the Stirling type, it will be understood that my furnace may be used with a boiler of other types, particularly with such as have vertical or nearly vertical water'tubes.

It will also be understood that While I have shown a bagasse burner, any other form of solid fuel fire box could be substituted therefor, and that similarly, while I have shown an oil burner in my fluid fuel fire box, any other form of fluid fuel may be used, such as gas or the like. In the appended claims, when I refer to solid fuel, it will be understood that I include therein all forms of fuel to be burned on a grate or its equivalent, and that by fluid fuel, I mean any form of gaseous or liquid fuel or pulverized fuel which may be blown into the fire box.

I claim 1. In combination, a steam boiler comprising vertically extending tubes with a baliie located near the front thereof and extending substantially parallel thereto, a furnace adapted to burn fuel of low heat value, a passage adapted to lead the gases from said furnace to the upper ends of said tubes, a fluid fuel furnace located above said first-mentioned furnace and constructed and arranged to deliver heated gases against and among the upper ends of the front tubes, boiler tubes being subjected to the direct radiant heat of said fluid fuel furnace, and means for directing the heated gases over the succeeding tubes of said boiler, both of said furnaces being located at one side of said boiler.

2. In combination, a steam boiler'comprising vertically extending tubes with a baffle located near the front thereof and extending substantially parallel thereto, a furnace adapted to burn fuel of low heat value, a passage adapted to lead the gases from said furnace to the upper ends of said tubes with change in direction during their passage from the furnace to the boiler, a fluid fuel furnace located above said first-mentioned furnace and constructed and arranged to deliver heated gases against and among the upper ends of the front tubes, boiler tubes being subjected to the direct radiant heat of said fluid fuel furnace, and means for directing the heated gases over the succeeding tubes of said boiler, both of said furnaces being located at one side of said boiler.

3. In combination, a steam boiler comprising vertically. extending tubes with a bafiie located near the front thereof and extending substantially parallel thereto, a furnace adapted to burn fuel of low heat value, a passage adapted to lead the gases from said furnace to the upper ends of said tubes, the parts being constructed and arranged to screen said furnace from the boiler tubes a fluid fuel furnace located above said first-mentioned furnace and constructed and arranged to deliver heated gases against and among the upper ends of the front tubes, boiler tubes being subjected to the direct radiant heat of said fluid fuel furnace, and means for directing the heated gases over the succeeding tubes of said boiler, both of said furnaces being located at one side of said boiler.

4. In combination, a steam boiler comprising vertically extending tubes with a baffle located near the front thereof and extending substantially parallel thereto, a furnace adapted to burn fuel of low heat value, a passage adapted to lead the gases from said furnace to the upper ends of said tubes, a fluid fuel furnace located above said first-mentioned furnace and constructed and arranged to deliver heated gases against and among the upper ends of the front tubes, boil-er tubes being subjected to the direct radiant heat of said fluid fuel furnace, and means for directing the heated gases over the su'cceeding'tubes of said boiler, both of said furnaces being located at one side of said boiler and constituting a front therefor.

GEORGE PALMER WARD. 

